The messages began appearing sometime after President Barack Obama's State of the Union address Wednesday night.

Jeff Ventura, spokesman for the House chief administrative officer, told the Associated Press that the sites were managed by a private vendor -- GovTrends of Alexandria, Va. Most House Web sites are managed totally by House technicians but individual offices are permitted to contract with a third party to manage new features and updates.

Ventura told the Associated Press that GovTrends let its guard down while performing an update, allowing the hacker to penetrate sites of individual members and committees overnight. Ventura said 18 House sites managed by GovTrends were defaced
last August. The House is looking into continued use of the company, he said.

There was no immediate word on who exactly was behind the hacking, but many believe it is the work of the "Red Eye Crew" in Brazil. The Web site PraetorianPerfect.com said all of the sites have one thing in common -- they all use the Joomla content management system.

On Wednesday, the White House's new cybersecurity coordinator for the White House, Howard Schmidt, said the government needs to invest more in the research and development of cybersecurity tools, according to The Hill. And Schmidt didn't agree with criticism that the administration is not moving fast enough to create a strategy for how the government should deal with it.

“There’s the perception out there that things aren’t getting done,” Schmidt told The Hill. “That can’t be farther from the truth.”